PELVIC INFORMATION AND SPINOHYPOTHALAMIC TRACT NEURONS

刺激盆腔内脏器官可显著改变 下丘脑神经元的活动。射击方面的这些变化可能是 重要的是参与控制几个自主的和 神经内分泌功能，包括调节分娩和 分娩。目前尚不清楚来自骨盆内脏的信息是如何 结构到达下丘脑。然而，使用几种解剖学方法 和生理技术，我们发现有大量的(多达 脊髓神经元直接投射到下丘脑。几个 投射到下丘脑的数百个神经元位于 处理内脏信息的腰骶部灰质方式 发生。拟议研究的工作假设是，至少 一些骨盆内脏信息被直接传输到 下丘脑通过脊丘脑束(SHT)。这一假说将 使用几种技术进行测试。逆行和顺行途径 建议进行示踪研究以确定下丘脑的哪些区域 接受来自脊髓区域的直接投射(即 腰椎节段)，这些节段参与处理许多 源自盆腔内脏器官的信息。双重标记 实验是为了确定脊髓的轴突是否 神经元直接投射到(反)催产素免疫反应神经元。 室旁核(PVN)和视上核(SON)。我们会 还要确定催产素能神经元是否接受来自SHT的输入 其远端树突上的轴突静脉曲张。在这些实验中， PVN和SON中的神经元将被厚厚的荧光黄填充， 固定截面。SHT神经元和催产素的轴突静脉曲张 含有神经元的细胞将被免疫细胞化学鉴定。并列式 SHT静脉曲张和充盈神经元之间的差异将被计数并 重建了。在其他的解剖学实验中，我们将确定 SHT神经元纤维是否与催产素免疫反应有关 PVN和SON内的神经内分泌神经元。电生理学研究 被提出用来确定神经元的反应特性 从腰骶髓投射到下丘脑。在这些 研究中，我们将使用骨盆内脏器官的量化刺激 (包括结肠/直肠、膀胱和女性生殖器官)和 腰骶部皮肤感受区。

Stimulation of pelvic visceral organs can markedly alter the activity of neurons In the hypothalamus. These changes in firing may be importantly involved In the control of several autonomic and neuroendocrine functions including the regulation of labor and parturition. It is unclear how information from pelvic visceral structures reaches the hypothalamus. However, using several anatomical and physiological techniques, we found that a large number (as many as 9000) spinal cord neurons project directly to the hypothalamus. Several hundred neurons that project to the hypothalamus are In areas of the lumbosacral gray manner in which processing of visceral information occurs. The working hypothesis of the proposed studies is that at least some pelvic visceral information is transmitted directly to the hypothalamus via the spinohypothalamic tract (SHT). This hypothesis will be tested using several techniques. Retrograde and anterograde tract tracing studies are proposed to determine which hypothalamic regions receive a direct projection from regions of the spinal cord (i.e. lumbosacral segments) that are involved in processing much of the information that originates In pelvic visceral organs. Double labeling experiments are proposed to determine whether the axons of spinal cord neurons project directly to (appose) oxytocin-immunoreactive neurons In the paraventricular nucleus (PVN) and supraoptic nucleus (SON). We will also determine whether oxytocinergic neurons receive an Input from SHT axonal varicosities on their distal dendrites. In these experiments, neurons In the PVN and SON will be filled with Lucifer Yellow In thick, fixed sections. The axonal varicosities of SHT neurons and oxytocin- containing neurons will be immunocytochemically Identified. Appositions between SHT varicosities and filled neurons will be counted and reconstructed. In additional anatomical experiments, we will determine whether fibers of SHT neurons appose oxytocin-immunoreactive neuroendocrine neurons In the PVN and SON. Electrophysiological studies are proposed to determine the response characteristics of neurons that project to the hypothalamus from the lumbosacral spinal cord. In these studies, we will use quantified stimulation of pelvic visceral organs (including the colon/rectum, bladder and female reproductive organs) and lumbosacral cutaneous receptive fields.